Tip the rice into a bowl, cover with cold water and whisk for 1-2 mins till the water goes cloudy (this is the starch). Drain, rinse and tip into a small pan. Add 300ml boiling water and a pinch of salt. Pop on a lid, bring to the boil then turn the heat down very low. Gently simmer for 25 mins till all the water has been absorbed, then take off the heat and leave to steam in the pan, lid on. This'll keep the rice nice and warm.
While the rice simmers, peel the onion and thinly slice it. Peel the garlic and crush or finely chop. Halve the chilli, flicking out the seeds and white pith for less heat, then finely chop it. Trim the ends off the aubergine and cut it into bite-sized chunks.
Pour 1 tbsp oil into a large pan and bring to a medium heat. Slide in the sliced onion and cook for 5 mins, stirring occasionally, till softened.
Stir the aubergines, garlic and chilli into the onions. Add a pinch or two of harissa (harissa is SPICY, so use as much or as little as you prefer. You can always add more later) along with 1 tsp each ground cumin and coriander. Sprinkle in a little salt and pepper. Cook for a further 4-5 mins, stirring occasionally.
Drain the chickpeas and rinse under cold water. Tip into the pan. Crumble in the stock cube. Pour in 200ml boiling water. Return to the boil, then lower the heat to a simmer. Cover the pan and gently cook for 20 mins, stirring from time to time, till the aubergine is soft and the sauce has thickened.
When the sauce has cooked, tip in the spinach leaves and stir till the leaves have wilted. Taste the sauce and add a little more harissa, salt and pepper if needed.
Pile the cooked basmati rice onto warm plates and serve with generous spoonfuls of the braised aubergine and chickpea sauce.